Methods for extinguishing petroleum-based fires, suppressing petroleum-released vapors and cleaning petroleum-contaminated surfaces

ABSTRACT

Compositions and methods for emulsifying a petroleum product that has been spilled upon a portion of the earth&#39;s surface or that is burning are based upon use of a nonionic, primary surfactant composition comprising a first ethoxylated sorbitol oleate and, preferably, a second ethoxylated sorbitol oleate, and a nonionic, secondary surfactant that is capable of stabilizing and solubilizing the primary surfactant composition such that the resulting emulsifying compositions have a hydrophilic/lipophilic balance between about 12.0 and about 13.5.

[0001] This application is a continuation-in-part of copending, commonlyassigned U.S. patent application Ser. No. 09/458,678, filed Dec. 10,1999, which is a continuation-in-part of U.S. patent application Ser.No. 09/081,461, filed May 19, 1998, and which in turn is acontinuation-in-part of U.S. application Ser. No. 08/701,063 filed Aug.21, 1996.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates, in general, to compositions andmethods for dispersing petroleum spills, and for acceleratingbiodegradation of such petroleum spills, and especially those that haveoccurred upon a body of water or any other surface.

[0004] 2. Related Art

[0005] Crude petroleums, as well as many products derived from them, areshipped from oil-producing locations to oil-consuming locations inocean-going vessels having huge capacities. Accidents in which the hullsof such vessels are breached and their contents spilled can causeserious damage to the environment. Unfortunately, such accidents are notat all uncommon. Land and offshore oil wells also can be a source of oilspills into ocean waters. Oil spills from such accidents may quicklyspread over many square miles of water surface. When they occur near, ordrift to, shorelines, such spills are particularly destructive towardlocal wildlife and plant life. Petroleum spills of this type also damageboats, fishing gear and harbor installations; and they greatly diminishthe value of the shore as a recreational resource. If not treated, suchspills require long periods to biodegrade; indeed, about 22 years isrequired to completely biodegrade one kilogram of crude oil by naturalprocesses.

[0006] Other oil spills are the result of deliberate actions such asacts of war, sabotage, and illegal discharge of cleaning fluids that areemployed to clean oil tankers in preparation for carrying a petroleumproduct that differs from the last product carried. Petroleum productsflowing through refineries and oil transport pipe systems are oftenspilled on land as well. Such land spills likewise require very longperiods; to biodegrade. Furthermore, since petroleum products areflammable, intense fires often occur as a result of such spills. Suchfires are fed by vapors released by the petroleum products, such vaporsincluding, e.g., ammonia and methane vapors. It is therefore highlyadvantageous to be able to contain and remove oil spills, and to arrestthe vapors so that they may not enter and pollute the atmosphere, assoon as possible after the event.

[0007] Many methods have been used to remove oil spills from waterand/or land. Such methods include physical removal of the petroleum fromthe water or land. chemical remediation of the spilled petroleum throughthe use of dispersants and so-called “sinking agents,” and, in somecases, intentionally burning floating petroleum slicks. Chemicalremediation through the use of liquid, oil dispersant agents is the mostfrequently employed clean-up method because such liquids can be readilyapplied to large oil spills and because this method is generally morecost-effective than physical remediation methods.

[0008] Most of the more effective methods of chemically remediating oilspills involve the use of various surfactant compositions. A surfactantis a surface-active agent whose molecules are composed of groups ofopposing polarity and solubility, i.e., surfactants usually have both anoil-soluble hydrocarbon chain and a water-soluble group. Surfactants canbe anionic, cationic, or nonionic. and they may be comprised of mixturesof any of these types of surfactants. Such surfactant mixtures ofteninclude other chemical agents, such as solvents, that enhance thedispersant capabilities of the surfactant. However, not all surfactantcompositions are effective in dispersing spilled oil products-and manyof the more effective ones have the drawbacks of being toxic and/or notbiodegradable.

[0009] Oil spill dispersant compositions employing a wide variety ofsurfactants are found in the patent literature. For example, U.S. Pat.No. 4,597,893 to Byford et al. teaches a dispersant composition fortreating oil on water. The composition comprises a nonionic surfactant,an anionic surfactant, a solvent, and water. The nonionic surfactant canbe one or more polyalkoxylated (5 to 55 moles) sorbitol or sorbitanfatty acid esters containing 40 moles of ethylene oxide and having ahydrophilic/lipophilic balance (HLB) of 9 to 12. The nonionic surfactantcomprises 8 to 58 weight percent of the overall composition. The anionicsurfactant is preferably a salt of an alkyl aryl sulfonate. The solventis a five- to ten-carbon primary alcohol, glycol, or glycol-ether, forexample, ethylene glycol monoburyl ether. A water component also may beadded as desired.

[0010] U.S. Pat. No. 3,793,2118 to Canevari et al. teaches dispersal ofoil slicks on water with a dispersant comprising a C₁₀ to C₁₂ aliphaticmonocarboxylic acid or sorbitan monoester thereof, a sorbitan monoesterpolyoxyalkylene adduct, and a dialkyl sulfosuccinate salt. Thedispersant can be applied to an oil slick with or without a solvent,such as, for example, paraffin (Isopar). The totalhydrophilic/lipophilic balance of these compositions is between 9 and11.5.

[0011] U.S. Pat. No. 4,382,873 to Gatellier et al. teaches a dispersantand biodegradant for oil that has been spilled on water. The dispersantcontains (1) an assimilable nitrogen compound derived from melarnine,(2) a hydroxy-providing compound such as a monoalcohol or a mono alkylderivative of ethylene glycol, (3) an assimilable phosphorus derivativeand (4) at least two of the following surface-active agents: sorbitanmonolaurate, sorbitan trioleate, sorbitan monooleate, anhydrosorbitolmonooleate, an ethoxylated primary alcohol (C₁₂-C₁₃), or PEG (300-400)mono- or di-oleate.

[0012] U.S. Pat. No. 3,959,134 to Canevari teaches an oil collectionagent that surrounds and collects oil that has been spilled on water.The agent is a mixture of a C₁₀ to C₂₀ saturated or unsaturated fattyacid or the sorbitan monoester thereof (e.g., SPANN), and a nonpolarsolvent such as isoparaffin.

[0013] U.S. Pat. No. 4,146,470 to Mohan et al. discloses a combinationof microorganisms and surfactants to disperse and digest oil slicks. Themicroorganism is preferably Micrococcus certificans. The surfactantmixture contains 15% to 75% by weight of (1) sorbitan monooleate (SPAN80) and polyoxyethylene sorbitan monooleate (TWEEN 80), or (2) an alkylglycoside, or a mixture of (1) and (2). These surfactants may or may notbe diluted in a paraffin solvent (Isopar). The HLB of the resultingcomposition is between 6.9 and 9.5.

[0014] There is, however, still a need for improved oil dispersantcompositions. This need follows from the fact that many prior artdispersants; (1) are not always effective in dispersing highly viscouscrude petroleum spills; (2) employ other components (in addition tononionic surfactants), e.g., anionic surfactants, solvents, and dialkylsulfosuccinate salts, that are not readily biodegradable, or containcompounds (e.g., certain anionic surfactants) that are themselvesextremely toxic to the environment, and (3) cannot sustain ahydrophilic/lipophilic balance at a level that serves to increase theirsolubility with water. Others have unacceptably short shelf lives and,hence, must be mixed in the field, and few, if any, are also capable ofserving as a fire-fighting agent as well as an oil dispersant.

[0015] 3. Solution to the Problem

[0016] Several of the above-noted patents show that ethoxylated sorbitololeates have been used in various dispersants used to treat oil spills;however, many ethoxylated sorbitol oleate-containing dispersants alsohave proven to be rather unstable and, hence, not well suited forlong-term storage and are therefore of rather limited practical utility.Consequently, there have been many attempts to increase the stability ofethoxylated sorbitol oleate-containing oil emulsifying agents by addingother surfactant ingredients such as, for example, primary alcohols tothem. However, primary alcohols alone have proved to be rather poorstabilizers for oil dispersants of this kind.

[0017] Applicant has, however, discovered that other types ofsurfactants having the hereinafter-described attributes can be added tocertain ethoxylated sorbitol oleate-containing oil-emulsifying agents toform water-miscible compositions that are very effective at emulsifyingspilled petroleum and/or petroleum products and are particularlycharacterized by their long shelf lives and by the fact that they employonly nonionic surfactants that are, in turn, characterized by theirrelatively low toxicity to the environment and by their relatively fastbiodegradability. The emulsifying compositions of the present inventionalso are capable of remediating oil spills on land as well as on water.

[0018] Applicant's emulsifying compositions have other utilities aswell. For example, they can be used as fire-fighting agents, andespecially against class B (hydrocarbon) fires in addition to class A(natural fuels), class C (electrical), and class D (metals) fires. Inparticular, whether the target petroleum or petroleum-based product(e.g., oil or fuel) is spilled or burning, the composition of thisinvention bounds the petroleum into a fine emulsion. In the case ofburning petroleum, the composition of this invention encapsulates thepetroleum droplets to form an emulsion and prevents escape of vaporsthat feed the fire, e.g., ammonia and/or methane (which are released bythe oil), thereby cutting off the source of and extinguishing the fire.When applied to a petroleum spill, the same emulsion extracts thepetroleum from the ground or water surface and is of a nature thatreadily accelerates the natural biodegradation process of the petroleumwhile maintaining a very low level of aquatic toxicity. Moreover, theherein-described oil dispersant compositions can be used as cleaningagents in those situations where the surface to be cleaned has a highhydrocarbon concentration, e.g., airport runways and aprons, as well asvarious container walls, for example, those of rail cars, tanker trucks,sea-going tankers, storage tanks, and automobile fuel tanks. In stillother applications, these compositions can be used to maintain and cleanoil-contaminated machine tool parts and to maintain the track beds,switches, etc., of railway systems. Applicant's compositions may even beused to accelerate the rate of biodegradation in sewage systems. Inaddition, tests on live animals have shown that applicant's compositionsare also exceptionally effective in the safe cleaning ofoil-contaminated wildlife, such as birds, without any observable sideeffects. Further, applicant's compositions have been independentlytested and found acceptable for use as cleaning agents in meat packingand poultry processing plants. As stated earlier herein, the compositionof this invention can also be used to prevent the escape of (i.e.,suppress) vapors released by petroleum or petroleum-based products,particularly spilled petroleum or petroleum-based products. Such vaporsare typically ammonia and/or methane vapors. In addition, thecompositions can be used to suppress ammonia and/or methane vaporsreleased at sites containing materials undergoing biodegradation ordecay, non-limiting examples of which include, e.g., sites containingpetroleum and/or petroleum-based products or other material undergoingbiodegradation or decay and releasing ammonia and/or methane vapors,compost (including decaying leaves) piles, animal waste sites, landfills containing petroleum or petroleum-based products or other materialundergoing degradation or decay and releasing methane or ammonia vapors,and the like.

SUMMARY OF THE INVENTION

[0019] The present invention provides improved compositions and methodsthat are particularly effective for emulsifying and/or dispersing apetroleum product that has been spilled upon a portion of the earth'ssurface, e.g., upon a body of salt water, a body of fresh water, or aportion of land. The petroleum products that can be emulsified anddispersed by applicant's compositions can be crude petroleum, orpetroleum-based products such as fuel oil, gasoline, jet fuel, and thelike. Regardless of the exact nature of the petroleum product spill,applicant's compositions should be comprised of a nonionic, primarysurfactant composition, a nonionic, secondary surfactant, and varyingamounts of water depending upon the use to which these emulsifyingand/or dispersing compositions will be applied.

[0020] Applicant's primary surfactant ingredient is an ethoxylatedsorbitol oleate and more preferably is a composition comprised of amixture of ethoxylated sorbitol oleates. That is to say that suchethoxylated sorbitol oleate mixtures will have a first ethoxylatedsorbitol oleate and at least one other ethoxylated sorbitol oleate. Inone particularly preferred mixture, the first ethoxylated sorbitololeate is ethoxylated sorbitol septaoleate and the second ethoxylatedsorbitol oleate is an ethoxylated sorbitol oleate selected from thegroup consisting of ethoxylated sorbitol trioleate and ethoxylatedsorbitol hexaoleate. Most preferably, the nonionic, primary surfactantwill comprise from about 45 to about 90 weight percent of the overall,end product, composition—as it is manufactured—but before it is dilutedwith water in the field-if indeed the end product composition is dilutedin the field.

[0021] The secondary surfactant ingredient of the herein-describedcompositions for dispersing spilled petroleum products is mostpreferably a nonionic surficant, or mixture of nonionic surfactants—andespecially those nonionic surfactants having a hydrophilic/lipophilicbalance (HLB) of about 10 to about 17. Most preferably, the secondarysurfactants of the herein-described compositions will be selected fromthe group consisting of linear ethoxylated secondary alcohols,polyoxyethylene aryl ether, ethoxylated fatty acid amides, ethoxylatedfatty acids and ethoxylated sorbitan monolaurate. If they are soemployed, such linear ethoxylated secondary alcohols preferably willcontain from about 7 moles to about 11 moles of ethylene oxide and havean HLB of about 10 to about 15. If so employed, a polyoxyethylene arylether ingredient will most preferably have an HLB greater than 15.5. Anethoxylated sorbitan monolaurate ingredient will, preferably, containfrom about 15 moles to about 26 moles of ethylene oxide and have an HLBof about 15 to about 17. Applicant's compositions preferably willcontain from about 20 to about 36 weight percent (as such compositionsare produced, but before they are further diluted, if they are in factfurther diluted, prior to use in the field) of such a nonionic,secondary surfactant (or mixture of such surfactants). The secondarysurfactant also should be capable of stabilizing and solubilizing theprimary surfactant to an extent such that the resulting manufacturedcomposition for emulsifying a petroleum product has an HLB from about12.0 to about 13.5.

[0022] The water component of applicant's manufactured compositions maybe inherently added to applicant's compositions as pan of themanufacturing process by virtue of the fact that water may be acomponent of applicant's oleate ingredient(s) (e.g., about 25 to 35%thereof) and/or by virtue of the fact that water is added as a distinctingredient in the manufacturing process. Preferably, the water in theoleate ingredients and/or secondary surfactant ingedient(s) and/or thewater added as a distinct ingredient in a separate step in themanufacturing process will be in quantities such that the resultingemulsifying compositions, as they are manufactured, will comprise fromabout 0.05 to about 30 weight percent water. The water component of themanufactured compositions of this patent disclosure (i.e., before anyaddition of water to such manufactured compositions is carried out inthe field) will preferably be less than about 30 weight percent of themanufactured product, and even more preferably will constitute less than20 weight percent of such manufactured products. A separate watercomponent used in the manufacturing process (ii any is in fact used) ispreferably deionized water, but fresh water or even salt water may beemployed for this purpose.

[0023] Certain optional components also may be added to theoil-emulsifying and/or dispersing_compositions of this patentdisclosure. These optional components preferably include anemulsion-stabilizing agent and/or a polyethylene glycol composition (andespecially a polyethylene glycol having a molecular weight from about200 to about 400). Such optional ingredient—containing oil-emulsifyingcomposition, as manufactured, but before they undergo any dilution inthe field, preferably will contain from about 1.0 weight percent toabout 4.0 weight percent of such an emulsion-stabilizing, agent, andfrom about 1.0 weight percent to about 2.0 weight percent of such apolyethylene glycol ingredient. When any, or all, of these optionalingredients are employed, it is highly preferred that resultingcompositions for emulsifying spilled petroleum, nonetheless, have the12.0 to 13.5 HLB value sought in those compositions that do not containany optional ingredients. It also should be noted that, regardless ofwhether or not these optional ingredients are employed, the end productcompositions for emulsifying spilled petroleum products are alsoparticularly characterized by their ready biodegradability, low levelsof toxicity to the environment, wide range of thermal stability, ease ofuse (owing to the fact that they can be premixed long before use withoutundergoing intervening phase separation) and, if need be, their abilityto fight fires as well as disperse oil.

[0024] To further enhance the rate of biodegradation of the emulsifyingcompositions of this patent disclosure in situations where the spillsite is deficient in nitrogen, phosphorus and oxygen, small amounts ofinorganic, commercially available fertilizers, such as mixtures of ureaformaldehyde and potassium orthophosphates, also may be added toapplicant's compositions as additional optional ingredients. Theseoptional fertilizer ingredients are preferably dissolved in water andadded to applicant's manufactured products (again, before such productsare diluted in the field) in concentrations such that no one of themforms more than about 0.5% of the total weight of the pre-field-dilutedemulsifying compositions of this patent disclosure. If it is alsodesired to lower the freezing point of these emulsifying compositions, anontoxic solvent such as, for example, diethylene glycol monobutyl etheralso may be added as yet another optional ingredient. This ingredient,if used at all, will be added in concentrations such that the diethyleneglycol monobutyl ether constitutes from about 1.0 to about 10.0 weightpercent of the manufactured, end product composition.

[0025] In some of the most preferred compositions of this patentdisclosure, prior to any field dilution, the ethoxylated sorbitol oleateingredient will be a mixture of ethoxylated sorbitol oleates comprising(1) about 45 to about 50 weight percent of a first ethoxylated sorbitololeate such as ethoxylated sorbitol septaoleate and wherein saidethoxylated sorbitol oleate contains from about 35 moles to about 45moles of ethylene oxide; and (2) from about 9 to about 10 weight percentof a second ethoxylated sorbitol oleate, and especially those selectedfrom the group of oleates consisting of ethoxylated sorbitol trioleateand ethoxylated sorbitol hexaoleate. Ethoxylated sorbitol trioleate andethoxylated sorbitol hexaoleate ingredients containing about 40 moles toabout 50 moles of ethylene oxide are particularly effective as second,or co-surfactant, ethoxylated sorbitol oleates. The remainder of thesemost preferred compositions will be comprised of from about 20 to about36 weight percent of the secondary surficant and from about 0.05 toabout 30.0 weight percent water.

[0026] The present invention also involves the use of certainhereinafter more fully described methods of contacting spilled petroleumwith applicant's emulsifying compositions. To these ends, applicant'scompositions may be added to a body of oil-polluted water, or land, inwidely varying “loading” amounts and/or composition concentrationsdepending on the end result desired, the type of oil that has beenspilled and/or the existing field conditions. It also should be notedthat, for the purpose of this patent disclosure the terms “loading, ” “,dosage, ” etc., should be regarded as being synonymous.) Be that as itmay, a “10% solution” of the herein-disclosed compositions may bethought of as a mixture that contains 10% by volume of the varioussurfactant ingredients (and optional ingredients, if any are used) thatconstitute the manufactured product and 90% by volume of locally addedwater. Such a 10% solution may, however, be even further diluted undercertain circumstances. For example, some of the most preferredsurfactant concentrations of applicant's compositions will be actuallyused in concentrations as low as about 3 volume percent of the overallmanufactured composition (for example, such relatively lowconcentrations are effective when applied, with high shear, to spills oflighter petroleum products, such as jet fuel, gasoline and the like). Onthe other hand, solution concentrations of about 20 volume percent ofthe manufactured composition and 80 volume percent local water areparticularly effective in dispersing somewhat heavier petroleum products(such as “light fuel oils”) and lubricating oils, especially when onlylow shear can be applied. In general, spills of oils heavier than No. 4lubricating oils, but lighter than No. 6 fuel oil, will call for use ofoil-emulsifying manufactured compositions of this patent disclosurediluted to an extent such that a locally provided water component willcomprise from about 80 to about 94 volume percent of the resultingmixture. Those compositions of this parent disclosure used to treat oilspills on land also will preferably be diluted to an extent that theycomprise from about 80 to about 94 volume percent water, and thosecompositions of this patent disclosure that are applied in the contextof an oil spill and fire also will most preferably comprise about 94volume percent water and about 6 volume percent of applicant'scompositions.

[0027] In general, spills of petroleum products less viscous than. say,No. 6 fuel oil and “bunker C” can be cleaned up using the manufacturedcompositions of this patent disclosure that have been diluted with waterin the field. Such field dilution of the manufactured forms of theherein-described compositions is generally prescribed when the spilledoil is “lighter than” No. 6 fuel oil. For example, spills of petroleumproducts lighter than No. 6 fuel oil may be treated with applicant'scompositions that have been diluted with water in the field to such anextent that the resulting manufactured composition/local water mixturethat is applied to the spill will, most preferably, be comprised of fromabout 10 to about 90 volume percent of the locally provided water (thatis to say, another 10 to 90 volume percent of local water will be added,regardless of the fact that a given manufactured composition may itselfalready be comprised of from about 0.05 to about 30 weight percentwater).

[0028] Indeed, in the case of spills of very light petroleum productssuch as gasoline, jet fuel and the like, manufactured compositions/localwater mixtures comprising up to 97 volume percent of local water (andhence, 3 volume percent of manufactured composition) may be employed,especially local agitation (e.g., provided by a ship's wake) also isavailable.

[0029] When the spilled petroleum product is a heavier petroleum product(e.g., crude petroleum and, generally speaking, a fuel oil as heavy asNo. 6 fuel oil), a particularly preferred method of application is toapply a manufactured composition having no more than about 30 weightpercent water (and more preferably a manufactured composition having nomore than about 10 weight percent water) to the spilled oil. In otherwords, the manufactured composition is applied without any addition ofwater in the field just prior to use. Water may, however, be added tothe resulting manufactured composition/spilled oil system after themanufactured composition is deployed upon the spilled oil.

[0030] Applicant has also found that the herein-described manufacturedcompositions (that is, those compositions existing prior to any fielddilution with locally available water) can produce total emulsificationwith about one (1) part of undiluted composition per about five (5) pansof a spill of No. 6 oil or bunker C oil. Most heavy crude oils can beemulsified by one (1) part of undiluted composition to ten (10) parts ofoil. In all cases, the application of the compositions of this patentdisclosure and the resulting emulsions vastly reduce the tendency of oilslicks on water to adhere to rock surfaces.

[0031] In many cases an emulsifying effect may be all that is requiredand/or desired to disperse a given oil spill, but in most casesbiodegradation of the emulsified oil/dispersant combination is the moredesired end result. In any case, the compositions of the presentinvention are highly biodegradable in the context of such oil spillemulsifications. Applicant's tests have shown that most emulsifiedoil/dispersant systems produced by the herein-described compositionswill biodegrade by about 80% within four (4) days of application of theherein-described compositions to an oil spill in water. Indeed,applicant has found that even within the first three (3) hours afterapplication of applicant's compositions, about 10% biodegradation of theoil/dispersant system is obtained. In other tests, applicant found thatup to about 97% biodegradation was obtained within 28 days afterapplication. In yet another laboratory test, total elimination of theoil/dispersant combination was observed within 8 days after applicationof some of applicant's compositions to certain “light” petroleumproducts.

[0032] The present invention further provides methods of using thecomposition of this invention to: (i) extinguish fires occurring inpetroleum or petroleum-based products, (ii) clean surfaces (includingthe body surfaces of wildlife, e.g., birds) contaminated with petroleumand/or petroleum-based product, (iii) accelerate biodegradation rate ofpetroleum or petroleum-based product, e.g., in a sewage system, and (iv)suppress production of methane and/or ammonia vapors by a petroleum orpetroleum-based product or other material undergoing biodegradation ordecay and releasing methane and/or ammonia vapors.

DETAILED DESCRIPTION OF THE INVENTION

[0033] 1. Particularly Preferred Formulations Re: Certain Applications.

[0034] As previously stated, applicant has found that particularly goodoil emulsification results are obtained when the secondary surfactant ofthe present invention stabilizes and solubilizes the primary surfactantcomposition to a degree such that the resulting, manufactured endproduct compositions (before any field dilution of such manufacturedcompositions takes place) have a hydrophilic/lipophilic balance (HLB)between about 12.0 and about 13.5. Those skilled in this art willappreciate that the term “HLB” as used herein is a well-known measure ofthe relative hydrophilicity or lipophilicity of a surfactantcomposition. Generally speaking, HLB values are obtained by dividing themolecular weight of the hydrophilic component of a compound by themolecular weight of the compound and multiplying the resulting number byselected adjuster values known to those skilled in this art. HLB valuesrange on a scale from 1 to more than 20, with 1 indicating the leasthydrophilic and 20 and above indicating the most hydrophilic.

[0035] Applicant has found that the stability of the dispersant/spilledoil emulsions produced by the compositions of this patent disclosure canbe further increased when small amounts of an emulsion-stabilizing agentare included in applicant's compositions. These emulsion-stabilizingagents are often used to provide steric stabilization of dispersedparticles (for example, literature published by Imperial ChemicalIndustries PLC (ICI) suggests use of their Hypermer A409® and HypermerA394® compositions for this purpose). Applicant has, however, found thatthe inclusion of such emulsion-stabilizing agents in theherein-described compositions for disversinc, spilled petroleum productsgreatly increases the stability of the resulting petroleum/compositionemulsion. This is an important finding because the increased longevityof the petroleum/composition emulsion enables the emulsion to be morecompletely biodegraded. Some of the better descriptions of suchemulsion-stabilizing agents are found in the technical literaturepublished by their manufacturers, and therefore, applicant herebyincorporates by reference the following publication describing theproperties of ICI's Hypermer® Polymeric Surfactants and Dispersants forIndustrial Applications”, ICI Americas Inc., 1994. Regardless of theidentity of their supplier, however, such emulsion-stabilizing agentsmay constitute from about 1.0 to about 4.0 weight percent of the overallmanufactured compositions of this patent disclosure.

[0036] 2. Particularly Preferred Methods of Formulating and DeployingCompositions

[0037] To prepare the emulsifying compositions of the present invention,the Primary surfactant composition is preferably made by first combiningthe first and the second ethoxylated sorbitol oleates under light,nonaerating agitation. If desired, the emulsion-stabilizing agent and/orthe polyethylene glycol are combined under moderately high shearconditions and then blended with the primary surfactant composition. Insome of the more preferred embodiments of this invention, the secondarysurfactant is added to the primary surfactant composition by blending itunder nonaerating shear conditions. Finally, the water component, ifdesired, is preferably added by blending under low shear conditions.Again, it should be understood that additional water can be incorporatedinto the manufactured compositions of this patent disclosure at a latertime, e.g., just prior to use, so that smaller volumes of themanufactured compositions of this parent disclosure may be transportedto a spill site.

[0038] The emulsifying compositions of the present invention may beapplied to petroleum spills on water or on land by conventional methodsknown to those skilled In the oil spill remediation arts, e.g., usingvarious tank and spray nozzle devices, or example, applicant'semulsifying compositions may be sprayed directly on petroleum spills onwater or on land with a small diameter hose equipped with a spray nozzleto supply a uniform spray. It also should be noted that it is notnecessary to apply the compositions using a high-pressure hose. Forlarge petroleum spills, applicant's compositions may be applied by usinga helicopter equipped with tanks having a dump spout that can beoperated from within the helicopter or such helicopters may be providedwith tanks and a pipe manifold systems that are affixed to a pluralityof spray nozzles.

[0039] For petroleum spills on land, dispension of the emulsifyingcompositions of this patent disclosure may be followed by physicalagitation of the soil and then flushing with water. Alternatively,applicant's compositions also may be dispensed under pressure, forexample, by a conventional fire extinguisher, whereby the pressuresupplied by such a device mixes the emulsifying composition with thepetroleum and simultaneously flushes it away.

[0040] Because of its emulsifying properties, the composition of thisinvention is useful in other applications as well, including, e.g.,extinguishing fires occurring in petroleum or petroleum-based products,cleaning surfaces (including the body surfaces of wildlife, e.g., birds)contaminated with petroleum and/or petroleum-based product, acceleratingbiodegradation rate of petroleum or petroleum-based product (e.g., in asewage system), and suppressing production of methane and/or ammoniavapors by a petroleum or petroleum-based product or other materialundergoing biodegradation or decay.

[0041] Thus, one aspect of the present invention is directed to a methodfor extinguishing a fire occurring in a petroleum or petroleum-basedproduct and caused by vapors released by the product, involving applyingthe composition of this invention to the fire and the product. As statedpreviously herein, the composition of this invention encapsulates thepetroleum droplets to form an emulsion and prevents escape of vaporsthat feed the fire, e.g., ammonia and/or methane (which are released bythe petroleum or petroleum-based product), thereby cutting off thesource of and extinguishing the fire.

[0042] A further aspect of the present invention is directed to a methodfor cleaning a surface contaminated with petroleum and/orpetroleum-based product, involving applying the composition of thisinvention to the surface. Non-limiting examples of suitable surfacesinclude those of airport runways, rail cars, tanker trucks, sea-goingtankers, storage tanks, automobile fuel tanks, machine tool parts, trackbeds, railway system switches, and meat packing and poultry processingplants. The surface can also be the body surface of a wildlife member,e.g., birds.

[0043] Yet another aspect of the present invention is directed to amethod for accelerating biodegradation rate of a petroleum orpetroleum-based product, involving applying the composition of thisinvention to the product. In one embodiment of this method, the productis disposed in a sewage system.

[0044] A still further aspect of this invention is directed to a methodfor suppressing production of methane and/or ammonia vapors by apetroleum or petroleum-based product or other material undergoingbiodegradation or decay and releasing ammonia and/or methane vapors,involving applying the composition of this invention to the product ormaterial.

[0045] This invention is further illustrated by reference to thefollowing tests conducted upon various formulations of the compositionsof this patent disclosure with respect to their dispersion abilities,biodegradation, and toxicity.

[0046] 3. Test Formulations.

[0047] Three emulsifying compositions were prepared having the followingthree formulations A, B, and C:

Emulsifier Formulation A

[0048] 45 weight percent—Ethoxylated sorbitol septaoleate, containing 40moles of ethylene oxide.

[0049] 9 weight percent—Ethoxylated sorbitol trioleate, containing 40 to50 moles of ethylene oxide.

[0050] 36 weight percent—linear ethoxylated secondary alcohol,containing 7 to 11 moles of ethylene oxide and having an HLB of between10 and 15, preferably 13.

[0051] 10 weight percent—water.

Emulsifier Formulation B

[0052] 50 weight percent—ethoxylated sorbitol septaoleate, containing 40moles of ethylene oxide.

[0053] 10 weight percent—ethoxylated sorbitol hexaoleate, containing 50moles of ethylene oxide.

[0054] 20 weight percent—polyoxylethylene aryl ether, having an HLB ofgreater than 15.5

[0055] 20 weight percent—water.

Emulsifier Formulation C

[0056] 45 weight percent—ethoxylated sorbitol septaoleate, containing 40moles of ethylene oxide.

[0057] 9 weight percent—ethoxylated sorbitol trioleate.

[0058] 26 weight percent—ethoxylated sorbitan monolaurate.

[0059] 20 weight percent—water.

[0060] a) Dispersion

[0061] Emulsifier formulation A was tested using a conventionallow-energy swirling flask dispersant effectiveness test. This test ismore fully described in 40 CFR Section 300 and said regulation isincorporated into this patent disclosure. The specific oil types used inapplicant's test were two standard preference oils, that is, Prudhoe BayCrude and South Louisiana Crude (a lighter oil than the Prudhoe BayCrude). The test was performed in “artificial sea water” (made fromInstant Ocean®) made to a salinity of 35 parts per thousand. One part(by weight) of emulsifying formulation A was used to 10 parts (byweight) of oil. The test was done with three or four replicate samples.Results were measured as the UV-VIS spectrophometric absorbance at 340nm. 370 nm. or 400 nm. The results of these tests are expressed below asthe percentage of the oil remaining dispersed for 10 minutes after allagitation had ceased. Those skilled in this art will appreciate that inthe oil remediation arts, a dispersion of 45% of the oil in such testsis regarded as being an acceptable test result. The results ofapplicant's tests are given in Table I and Table II. TABLE I %Dispersibility of Prudhoe Crude Replicate 1 Replicate 2 Replicate 3Absorbance at 340 nm 45 54 47 Absorbance at 370 nm 44 53 46 Absorbanceat 400 nm 43 53 45 Average = SD 44 = 1 53 = 1 46 = 1 Overall average =SD 48 = 4

[0062] TABLE II % Disversibility of South Louisiana Crude Replicate 1Replicate 2 Replicate 3 Replicate 4 Absorbance 65 68 67 65 at 340 nmAbsorbance 64 67 67 64 at 370 nm Absorbance 63 66 65 63 at 400 nmAverage = SD 64 = 0.7 67 = 1.0 66 = 0.9 64 = 0.7 Overall 65 = 1.3average = SD

[0063] Tables I and II clearly show that emulsifying, formulation Adisperses 48% of the Prudhoe Bay Crude and 65% of the South LouisianaCrude.

[0064] Applicant also conducted emulsifying and dispersing tests withemulsifying formulation A using concentrations as low as about 3%solutions with respect to “lighter” oil products such as No. 2 dieseloil, under moderately high shear conditions. However, applicant alsofound that if less agitation is available, somewhat higherconcentrations, e.g., 15% solutions, were often required to emulsify anddisperse a like amount of the No. 2 diesel oil. By way of contrast, inorder to emulsify and disperse No. 6 fuel oil, a 100% solution offormulation A was applied at a ratio of one (1) part of composition to10 parts of oil under moderate agitation to produce the desiredemulsification effects.

[0065] b) Biodegradation The relatively quick and extensivebiodegradation property of the oil-emulsifying compositions of thispatent disclosure is one of their more important properties. It wastested using various tests known to the art including the E.M.P.A. test(the E.M.P.A. is a Swiss government organization charged with certifyingoil-dispersant and emulsifying compositions). To this end, a standardtest (EMPA SOP 720) was performed on emulsifying formulation A todetermine the rate of biodegradation of this formulation in combinationwith an oil sludge over a period of 28 days. The amount of degradationwas determined by measuring the percentage of the initial oxygenconcentration. In such tests, applicant found that about 73% of acombination of emulsifying formulation A/oil sludge (at a concentrationof 118 mg of formulation A per liter of oil sludge) was biodegraded byday 3 of the experiment, and about 81% was biodegraded by day 21. Thefurther results of this test are shown in Table III. TABLE III % InitialTotal Oxygen Day Concentration (TOC) 0.1 10 1 30 3 73 7 75 14 79 21 8128 81

[0066] Consequently, these test indicate that the values for thebiodegradation of emulsifying formulation A in combination with oilsludge are well within the acceptable, range for certification ofemulsifying formulation A by the E.M.P.A.

[0067] Applicant's own laboratory and field tests showed more than 81%degradation of a combination of oil and emulsifying formulation A wasobserved within four (41) days of application. In these tests, about 10%of the biodegradation occurred within the first three (3) hours afterapplication of formulation A. In other tests, more than 97% of theoil/emulsifying formulation A combination was biodegraded after 28 days.Total elimination of the oil/formulation A combination in eight (8) dayswas observed in vet another laboratory test. The significance of theseresults can be better appreciated when one considers that natural lairbiodegradation of one (1) kilogram of crude oil may take as long as 22years.

[0068] c) Toxicity Another advantageous attribute of applicant'semulsifying/dispersant compositions is their low toxicity, especiallytoward aquatic life. In order to verify this low toxicity, a sample offormulation B (as described above) was tested for toxicity against twoaquatic organisms, brine shrimp (Artemia sp.) and a species of fish(Fundulus heteroclitus). The test procedure involved exposing theorganisms to increasing concentrations of emulsifying formulation Balone and to a combination of equal amounts of emulsifying formulation Band diesel oil and determining, the LC₅₀ (the concentration offormulation B alone or formulation B/oil combination that kills 50% ofthe organisms) after 8 hours of exposure for the shrimp and 96 hours ofexposure for the fish. The LC₅₀ values for emulsifying formulation Balone were compared with LC₅₀ values for other dispersants of comparableefficiency as listed in the National Contingency Plan defined in 40 CFRSection 300. The results are shown in Table IV. TABLE IV LC₅₀ LC₅₀ (ppmafter 96 hours) (ppm after 48 hours) Dispersant for Fundulus for ArtemiaEmulsifying formulation B 4900 2500 D-9  115 630 D-27 100 60 D-61 180 60D-62 71 8 D-64 109 155

[0069] The data in Table IV show that, for example, only 115 ppm (partsper million) of product D-9 will kill one-half of the fish in 96 hours,whereas 4900 ppm of applicant's emulsifying formulation B is required tokill one-half of the fish in the same period. For Artemia sp., thecomparative dispersants kill one-half of the shrimp in 48 hours atconcentrations of 8 to 630 ppm. Emulsifying formulation B, by contrast,had an LC₅₀ of 2500 ppm against Artemia sp. These tests indicate thatemulsifying formulation B is less toxic than comparative dispersants byan order of magnitude.

[0070] When emulsifying formulation B was mixed with an equal amount ofdiesel oil and this diesel oil/emulsifier combination was tested fortoxicity against organisms in the same way as described above, the LC₅₀for Artemia sp. was 1500 ppm, and the LC₅₀ for Fundulus sp. was 1400ppm. Again, these toxicity values are far lower than the LC₅₀ valuesshown in Table IV for comparative dispersants without oil.

[0071] The above disclosure sets forth a number of embodiments of thepresent invention. Those skilled in this art will however appreciatethat other embodiments, not precisely set forth, also could be practicedunder the teachings of the present invention and that the scope of thisinvention should only be limited by the scope of the following claims.

What is claimed is:
 1. A method for extinguishing a fire occurring in apetroleum or petroleum-based product and caused by vapors released bysaid product, comprising applying to said fire and said product acomposition comprising: (a) a nonionic primary surfactant comprising anethoxylated sorbitol oleate; (b) a nonionic secondary surfactantselected from the group consisting of linear ethoxylated secondaryalcohols, polyoxyethylene ethers, ethoxylated sorbitan monolaurates,ethoxylated fatty acid amides and ethoxylated fatty acids and containingabout 7 moles to about 26 moles of ethylene oxide and comprising fromabout 20 to about 36 weight percent of said composition, and whereinsaid nonionic secondary surfactant is capable of stabilizing andsolubilizing said nonionic primary surfactant such that said compositionhas a hydrophilic/lipophilic balance between about 12.0 and about 13.5;and (c) water; wherein said composition arrests said vapors released bythe product, thereby extinguishing the fire.
 2. A method according toclaim 1, wherein the product is spilled petroleum oil and/or fuel.
 3. Amethod according to claim 1, wherein the primary surfactant isethoxylated sorbitol septaoleate.
 4. A method according to claim 1,wherein the secondary surfactant has a hydrophilic/lipophilic balance offrom about 10 to about
 17. 5. A method according to claim 1, wherein thecomposition further comprises an emulsion-stabilizing agent.
 6. A methodaccording to claim 1, wherein the composition further comprises apolyethylene glycol component having a molecular weight of from about200 to about
 400. 7. A method for cleaning a surface contaminated withpetroleum and/or petroleum-based product, comprising applying to saidsurface a composition comprising: (a) a nonionic primary surfactantcomprising an ethoxylated sorbitol oleate; (b) a nonionic secondarysurfactant selected from the group consisting of linear ethoxylatedsecondary alcohols, polyoxyethylene ethers, ethoxylated sorbitanmonolaurates, ethoxylated fatty acid amides and ethoxylated fatty acidsand containing about 7 moles to about 26 moles of ethylene oxide andcomprising from about 20 to about 36 weight percent of said composition,and wherein said nonionic secondary surfactant is capable of stabilizingand solubilizing said nonionic primary surfactant such that saidcomposition has a hydrophilic/lipophilic balance between about 12.0 andabout 13.5; and (c) water.
 8. A method according to claim 7, wherein theprimary surfactant is ethoxylated sorbitol septaoleate.
 9. A methodaccording to claim 7, wherein the secondary surfactant has ahydrophilic/lipophilic balance of from about 10 to about
 17. 10. Amethod according to claim 7, wherein the composition further comprisesan emulsion-stabilizing agent.
 11. A method according to claim 7,wherein the composition further comprises a polyethylene glycolcomponent having a molecular weight of from about 200 to about
 400. 12.A method according to claim 7, wherein the surface is selected from thegroup consisting of airport runways, rail cars, tanker trucks, sea-goingtankers, storage tanks, automobile fuel tanks, machine tool parts, trackbeds, railway system switches, and meat packing and poultry processingplants.
 13. A method according to claim 7, wherein the surface is a bodysurface of a wildlife member.
 14. A method according to claim 13,wherein the wildlife member is a bird.
 15. A method for acceleratingbiodegradation rate of a petroleum or petroleum-based product,comprising applying to said product a composition comprising: (a) anonionic primary surfactant comprising an ethoxylated sorbitol oleate;(b) a nonionic secondary surfactant selected from the group consistingof linear ethoxylated secondary alcohols, polyoxyethylene ethers,ethoxylated sorbitan monolaurates, ethoxylated fatty acid amides, andethoxylated fatty acids and containing about 7 moles to about 26 molesof ethylene oxide and comprising from about 20 to about 36 weightpercent of said composition, and wherein said nonionic secondarysurfactant is capable of stabilizing and solubilizing said nonionicprimary surfactant such that said composition has ahydrophilic/lipophilic balance between about 12.0 and about 13.5; and(c) water.
 16. A method according to claim 15, wherein said petroleum orpetroleum-based product is disposed in a sewage system.
 17. A methodaccording to claim 15, wherein the primary surfactant is ethoxylatedsorbitol septaoleate.
 18. A method according to claim 15, wherein thesecondary surfactant has a hydrophilic/lipophilic balance of from about10 to about
 17. 19. A method according to claim 15, wherein thecomposition further comprises an emulsion-stabilizing agent.
 20. Amethod according to claim 15, wherein the composition further comprisesa polyethylene glycol component having a molecular weight of from about200 to about
 400. 21. A method for suppressing production of methaneand/or ammonia vapors by a petroleum or petroleum-based product or othermaterial undergoing degradation or decay and releasing methane and/orammonia vapors, comprising applying to said product or material acomposition comprising: (a) a nonionic primary surfactant comprising anethoxylated sorbitol oleate; (b) a nonionic secondary surfactantselected from the group consisting of linear ethoxylated secondaryalcohols, polyoxyethylene ethers, ethoxylated sorbitan monolaurates,ethoxylated fatty acid amides and ethoxylated fatty acids and containingabout 7 moles to about 26 moles of ethylene oxide and comprising fromabout 20 to about 36 weight percent of said composition, and whereinsaid nonionic secondary surfactant is capable of stabilizing andsolubilizing said nonionic primary surfactant such that said compositionhas a hydrophilic/lipophilic balance between about 12.0 and about 13.5;and (c) water.
 22. A method according to claim 21, wherein the productor material is a spilled petroleum or petroleum-based product.
 23. Amethod according to claim 21, wherein the material is compost.
 24. Amethod according to claim 21, wherein the product or material isdisposed in a landfill.
 25. A method according to claim 21, wherein theprimary surfactant is ethoxylated sorbitol septaoleate.
 26. A methodaccording to claim 21, wherein the secondary surfactant has ahydrophilic/lipophilic balance of from about 10 to about
 17. 27. Amethod according to claim 21, wherein the composition further comprisesan emulsion-stabilizing agent.
 28. A method according to claim 21,wherein the composition further comprises a polyethylene glycolcomponent having a molecular weight of from about 200 to about 400.